PHIL Experimentation on Fault Ride Through Behavior of Doubly Fed Induction Generator-Based Wind System in the Presence of Fault Current Limiter
M V Gururaj, Narayana Prasad Padhy
Abstract
In the literature, the fault ride through (FRT) studies of the doubly fed induction generator (DFIG)-based wind system consider fault to occur after the fault current limiter (FCL) with respect to the DFIG system. In this article, the fault is considered before FCL and the power hardware in the loop (PHIL) experimentation is performed. Results demonstrate that the occurrence of the fault before FCL can worsen the FRT of the DFIG system. To address this, a novel arrangement of FCL with four power electronic switches in a particular fashion has been suggested. This arrangement allows the perception of fault occurring before FCL as after FCL due to the alternate path of power flow thereby improving the FRT of the DFIG. Furthermore, a quick fault detection and switching technique has been developed which is able to detect the fault by comparing the instantaneous value of the phase current with the threshold. Thereby, it is possible to achieve on/off of the switches upon the fault occurrence with negligible time delay. In order to validate the effectiveness of the proposed technique, the PHIL experimentation is performed at sub/supersynchronous mode of operations (±0.1 slip), different fault resistances (6, 20 Ω), delay time (40 ms), and various fault perception instants (negative, zero, positive). The results justify the effectiveness of the proposed arrangement in improving FRT of the DFIG when a fault occurs before the FCL with respect to the DFIG in comparison to the existing literature and in the absence of FCL in the system.